The first thing you have probably checked is if the class
that is supposed to be missing according to the Error message
is present on your Linux server.
If it is, the second thing you should check if you have the
same Java Virtual Machine on both systems. Java throws a
NoClassDefFoundError for instance if the JVM is 1.3 whereas
the code you try to run on the JVM was compiled with JDK 1.4.
br,
Bruno